Elise Lefevre received the Frank Goes Prize in the Civil Engineering category from the Fédération des Entrepreneurs Généraux de la Construction

In her thesis, Elise Lefevre investigated the hydro-mechanical performance of compacted earth as a sustainable alternative to conventional, energy-intensive building materials. The study focused on a novel stabilization technique, Enzyme-Induced Calcite Precipitation (EICP), which has demonstrated potential in enhancing the engineering properties of earthen materials (e.g., durability against water erosion) while preserving their environmental sustainability. This experimental method utilizes crude urease extracted from soybeans to catalyze the precipitation of calcium carbonate, which binds soil particles and improves the mechanical properties and durability of the materials. The research specifically addressed challenges associated with the EICP protocol, including the extraction of urease from soybeans. It compared the use of soybeans in the form of crude juice extract versus fine powder, as well as the effects of adding a cementing solution and facilitating calcite precipitation in fine-grained soils. A series of laboratory tests were conducted to evaluate the impact of temperature and relative humidity on the strength, stiffness, and water resistance of compacted EICP-stabilized samples. The results of this work represent a significant advancement in understanding the best practices, as well as the advantages and limitations, of the EICP stabilization technique for manufacturing compressed earth bricks for building applications.